Journal article

Publication year: 1993

Pages: 99-102

Journal: Plant and Soil

Volume number: 155

Issue number: 1

ISSN: 0032-079X

DOI Link: https://doi.org/10.1007/BF00024993

Publisher: Springer

Abstract: 
The re-uptake of sugars driven by the proton gradient was studied in sugar net-release and net-uptake experiments using roots of intact maize (Zea mays cv. Blizzard) and field bean (Vicia faba L. cv. Alfred) plants. The net release of sugars into the root medium (0.1 mM CaSO4) was stimulated by: the protonophore CCCP (10 mu M); the sulfhydryl reagent NEM (300 mu M); the specific inhibitor of plasmalemma ATPase vanadate (0.5 mM); and the inhibitor of the glucose carrier phlorizin (2 mM). Net uptake of glucose, fructose and arabinose from 10 mu M external concentrations was also inhibited by these substances. Surprisingly fusicoccin, a stimulator of net proton release did not effect net sugar uptake. Medium pH values only influenced sugar net uptake if the pH was above 7. It is concluded that a degradation of the proton gradient across the plasmalemma stimulates net sugar release because of disturbed re-uptake of sugars ( in particular glucose) via a proton/sugar cotransport system. Thus, the retention of sugars by root cells not only depends on the plasmalemma permeability but also on the electro-chemical proton gradient. If an electro-chemical proton gradient is established by plasmalemma ATPase activity the re-uptake of sugars by proton/sugar cotransport minimizes the release of sugars into the rhizosphere.

Harvard Citation style: Mühling, K., Schubert, S. and Mengel, K. (1993) Mechanism of sugar retention by roots of intact maize and field bean plants, Plant and Soil, 155(1), pp. 99-102. https://doi.org/10.1007/BF00024993

APA Citation style: Mühling, K., Schubert, S., & Mengel, K. (1993). Mechanism of sugar retention by roots of intact maize and field bean plants. Plant and Soil. 155(1), 99-102. https://doi.org/10.1007/BF00024993